Samsung MAX-610 User manual

© Samsung Electronics Co.,Ltd. March 1997 Code no. AH68-20154A
3 CD CHANGER MINI MINI
COMPONENT SYSTEM
MAX-610
SERVICEManual
3CD CHANGER MINI COMPONENT CONTENTS
1. Precautions
2. Specifications
3. Disassembly and Reassembly
4. Alignment and Adjustments
5. Special Circuit Descriptions
6. Troubleshooting
7. Exploded Views and Parts List
8. Electrical Parts List
9. Block Diagrams
10. PCB Diagrams
11. Wiring Diagram
12. Schematic Diagrams

1. Precautions
Follow these safety, servicing and ESD precautions to prevent damage and protect against potential hazards
such as electrical shock and X-rays.
Samsung Electronics 1-1
1-1 Safety Precautions
1. Be sure that all of the built-in protective
devices are replaced.
2. When reinstalling the chassis and its
assemblies, be sure to restore all protective
devices, including control knobs and
compartment covers.
3. Make sure that there are no cabinet
openings through which people--
particularly children--might insert fingers
and contact dangerous voltages. Such
openings include the spacing between the
picture tube and the cabinet mask,
excessively wide cabinet ventilation slots,
and improperly fitted back covers.
4. Design Alteration Warning:
Never alter or add to the mechanical or
electrical design of the unit. Example: Do
not add auxiliary audio or video connec-
tors. Such alterations might create a safety
hazard. Also, any design changes or addi-
tions will void the manufacturer's warran-
ty.
5. Leakage Current Hot Check (Figure 1-1):
Warning: Do not use an isolation
transformer during this test. Use a leakage-
current tester or a metering system that
complies with American National Standards
Institute (ANSI C101.1, Leakage Current for
Appliances), and Underwriters Laboratories
(UL Publication UL1410, 59.7).
With the unit completely reassembled, plug
the AC line cord directly into a 120V AC
outlet. With the unit's AC switch first in
the ON position and then OFF, measure the
current between a known earth ground
(metal water pipe, etc.) and all exposed
metal parts. Examples: Handle brackets,
metal cabinets, screwheads and control
shafts. The current measured should not
exceed 0.5 milliamp. Reverse the power-
plug prongs in the AC outlet and repeat.
6. Insulation Resistance Cold Check:
(1) With the unit's AC plug disconnected
from the AC source, connect an electrical
jumper across the two AC prongs. (2) Set
the power switch to ON. (3) Measure the
resistance between the shorted AC plug and
any exposed metallic parts. Example:
Screwheads, antenna, control shafts or
handle brackets.
If any of the exposed metallic parts has a
return path to the chassis, the measured
resistance should be between 1 and 5.2
megohms. If there is no return path, the
measured resistance should be "infinite." If
the resistance is outside these limits, a shock
hazard might exist. See Figure 1-2
Device
Under
Test
(Reading should
not be above
0.5mA)
Leakage
Currant
Tester
Earth
Ground
Test all
exposed metal
surfaces
Also test with
plug reversed
(using AC adapter
plug as required)
2-Wire Cord
Antenna
Terminal
Exposed
Metal Part
ohm Ohmmeter
Fig. 1-1 AC Leakage Test
Fig. 1-2 Insulation Resistance Test

Samsung Electronics1-2
1-1 Safety Precautions (Continued)
7. Components, parts and wiring that appear
to have overheated or that are otherwise
damaged should be replaced with parts
that meet the original specifications.
Always determine the cause of damage or
overheating, and correct any potential
hazards
8. Observe the original lead dress, especially
near the following areas: Antenna
wiring, sharp edges, and especially the
AC and high voltage power supplies.
Always inspect for pinched, out-of-place,
or frayed wiring. Do not change the
spacing between components and the
printed circuit board. Check the AC
power cord for damage. Make sure that
no wires or components touch thermally
hot parts.
9. Product Safety Notice:
Some electrical and mechanical parts
have special safety-related characteristics
which might not be obvious from visual
inspection. These safety features and the
protection they give might be lost if the
replacement component differs from the
original--even if the replacement is rated
for higher voltage, wattage, etc.
10 Components that are critical for safety are
indicated in the circuit diagram by
shading, or . Use replacement
components that have the same ratings,
especially for flame resistance and
dielectric strength specifications. A
replacement part that does not have the
same safety characteristics as the original
might create shock, fire or other hazards.
1-2 Servicing Precautions
1. Servicing precautions are printed on the
cabinet. Follow them.
2. Always unplug the unit's AC power cord
from the AC power source before
attempting to: (a) Remove or reinstall any
component or assembly, (b) Disconnect an
electrical plug or connector, (c) Connect a
test component in parallel with an
electrolytic capacitor.
3. Some components are raised above the
printed circuit board for safety. An
insulation tube or tape is sometimes used.
The internal wiring may be clamped to
prevent contact with thermally hot
components. Reinstall all such elements to
their original position.
4. After servicing, always check that the
screws, components and wiring have been
correctly reinstalled. Make sure that the
portion around the serviced part has not
been damaged.
5. Check the insulation between the blades of
the AC plug and accessible conductive parts
(examples: metal panels, input terminals
and earphone jacks).
6. Insulation Checking Procedure: Disconnect
the power cord from the AC source and
turn the power switch ON. Connect an
insulation resistance meter (500V) to the
blades of the AC plug.
The insulation resistance between each
blade of the AC plug and accessible
conductive parts (see above) should be
greater than 1 megohm.
7. Never defeat any of the B+ voltage
interlocks. Do not apply AC power to the
unit (or any of its assemblies) unless all
solid-state heat sinks are correctly installed.
8. Always connect a test instrument's ground
lead to the instrument chassis ground
before connecting the positive lead; always
remove the instrument's ground lead last.
Precautions
Warning1: First read the "Safety Precautions" section of this manual. If some unforeseen circumstance creates a conflict
between the servicing and safety precautions, always follow the safety precautions.

Samsung Electronics 1-3
1-3 Precautions for Electrostatically Sensitive Devices (ESDs)
1-4 Special Precautions and Warning Labels for Laser Products
1. Some semiconductor ("solid state") devices
are easily damaged by static electricity.
Such components are called Electrostatically
Sensitive Devices (ESDs). Examples include
integrated circuits and some field-effect
transistors. The following techniques will
reduce the occurrence of component
damage caused by static electricity.
2. Immediately before handling any
semiconductor components or assemblies,
drain the electrostatic charge from your
body by touching a known earth ground.
Alternatively, wear a discharging
wrist-strap device. (Be sure to remove it
prior to applying power--this is an electric
shock precaution.)
3. After removing an ESD-equipped assembly,
place it on a conductive surface such as
aluminum foil to prevent accumulation of
electrostatic charge.
4. Do not use freon-propelled chemicals.
These can generate electrical charges that
damage ESDs.
5. Use only a grounded-tip soldering iron
when soldering or unsoldering ESDs.
6. Use only an anti-static solder removal
device. Many solder removal devices are
not rated as "anti-static" (these can
accumulate sufficient electrical charge to
damage ESDs).
7. Do not remove a replacement ESD from its
protective package until you are ready to
install it. Most replacement ESDs are
packaged with leads that are electrically
shorted together by conductive foam,
aluminum foil or other conductive
materials.
8. Immediately before removing the protective
material from the leads of a replacement
ESD, touch the protective material to the
chassis or circuit assembly into which the
device will be installed.
9. Minimize body motions when handing
unpackaged replacement ESDs. Motions
such as brushing clothes together, or lifting
a foot from a carpeted floor can generate
enough static electricity to damage an ESD.
Precautions
UL : Manufactured for U.S.A. Market.
CSA : Manufactured for Canadian Market.
EU : Manufactured for European Market.
SCAN : Manufactured for Scandinavian
Market.
This Product Complies with
DHHS Rules 21CFR, Sub
chapter J.At date of Manu-
facture
(UL)
(SCAN)
(EU)
CERTIFIED ONLY TO CANADIAN
ELECTRICAL CODE.
CERTIFIE EN VERTU DU CODE
CANADIAN DE LELETRICITE
SEULEMENT
(CSA)
CLASS 1
LASER PRODUCT
(EU)
Fig. 1-3 Warning Labels (Location: Enclosure Block)
Fig. 1-4 Warning Labels (Location: Disc Clamper, Inner Side of Unit Door or Nearby Unit Chassis )
CAUTION : INVISIBLE LASER RADIATION WHEN OPEN
AND INTERLOCKS DEFEATEO AVOIDEXPOSURE TO BEAM
ADVARSEL: USYNLIG LASERSTRÅLING VED ABNING
NÅR SIKKERHEDSAFBRYDERE ER UDE AF FUNKTION
UNDGA UDSAETTELSE FOR STRALING
VARO:AVATTAESSA JA SUOJALUKITUS OHITETTAESSA
OLET ALTTINA NAKYMATTÖMALLE LASERSATEILYLLE ALA
KATSO SATEESEEN!
VARNING:OSYNLIG LASERSTRÅLNING NAR DENNA DEL
AR OPPNAD OCH SPARREN AR URKOPPLAD BETRAKTA
EJSTRÅLEN!

Samsung Electronics1-4
1-4 Special Precautions and Warning Labels for Laser Products (Continued)
1-4-1 Warnings
1. When servicing, do not approach the LASER
exit with the eye too closely. In case it is
necessary to confirm LASER beam emission,
be sure to observe from a distance of more
than 30 cm from the surface of the objective
lens on the optical pick-up block.
2. Do not attempt to handle the objective lens
when the DISC is not on the tray.
1-4-2 Laser Diode Specifications
Material: GaAs+ GaAlAs
Wavelength: 760-800 nm
Emission Duration: Continuous
Laser Output: 0.2 mw (measured at a
1.6 mm distance from the objective lens
surface on the optical pick-up block.)
1-4-3 Handling the Optical Pick-up
1. Static electricity from clothing or the body
may cause electrostatic breakdown of the
laser diode in the Optical Pickup. Follow
this procedure:
2. Place a conductive sheet on the work bench
(i.e., the black sheet used for wrapping
repair parts.) Note: The surface of the work
bench should be covered by a copper
ground plane, which is grounded.
3. The repair technician must wear a wrist
strap which is grounded to the copper sheet.
4. To remove the Optical Pickup block:
Place the set on the conductive sheet, and
momentarily touch the conductive sheet
with both hands. (While working, do not
allow any electrostatic sources--such as
clothes--to touch the unit.)
5. Ground the "Short Terminal" (located on the
PCB, inside the Pickup Assembly) before
replacing the Pickup. This terminal should
be shorted whenever the Pickup Assembly
is lifted or moved.
6. After replacing the Pickup, reopen the Short
Terminal. See diagrams below:
Precautions
THE UNIT
(1) WRIST-STRAP
FOR GROUNDING 1M
1M
CONDUCTIVE SHEET
short
terminal short terminal short
terminal short
terminal
SOH91VI(LDP) SOH91CI(CAR,walkman) SOH94T4N
(CMS-V10,CMS-V30)
SOH-A1
(CMS-V10,CMS-V30)

2. Product Specfications
Samsung Electronics 2-1
General
Amp
Cassette
Tuner
Compact Disc
FM
MW
LW
Power source
Power consumption
Dimensions (mm)
Power output
Total harmonic distortion
Frequency range
Signal to noise ratio
Channel separation
Input sensitivity
Frequency range
Usable sensitivity
Signal to noise ratio
IF rejection ratio
Total harmonic distoration
Separation (Stereo)
Frequency range
Usable sensitivity
Signal to noise ratio
IF rejection ratio
Total harmonic distortion
Frequency range
Usable sensitivity
IF rejection ratio
Frequency range
WOW FLUTTER
Erasing effect
Signal to noise ratio
Total harmonic distortion
Frequency response
Signal to noise ratio
Channel separation
Total harmonic distortion
125Hz ~ 12.5KHz
0.15%
60 dB
40 dB
2.5%
20Hz ~ 20KHz(±1dB)
90 dB(1kHz 0dB)
80 dB(1kHz 0dB)
0.05%(1kHz 0dB)
87.5 ~ 108MHz
1µV
62 dB
60 dB
0.45%
35 dB
522 ~ 1611KHz
600µV
40 dB
30 dB
2%
146 ~ 290KHz
1500µV
25 dB
35W / Ch(6Ω) (THD 1%)
0.08%
20Hz ~ 20kHz
75 dB
50 dB
400mV
230V
150W
270(W) x 317(H) x 340(D)
* Specifications are subject to change without notice.

3. Disassembly and Reassembly
3-1 Cabinet-Top
1. Remove 11 screws holding the Cabinet-Top.
2. Lift the back of the Cabinet-Top and slide it to the rear to remove.
Figure 3-1
Samsung Electronics 3-1

Figure 3-2
3-2 Samsung Electronics
3-2 CD-Mecha, Door-CD
Disassembly and Reassembly
1. After power is connected :
- Turn power on and open the tray using the open/close key
2. After disconnecting power :
Turn the Gear clockwise using the hand as shown in figure 3-2-1.
Pull the Tray in the direction of arrow @.
3. Remove 4 screws $,%and lift the CD-Mecha.
4

4


2

Tray

1
5

Figure 3-2-1

3-3 Cabinet-Rear and Main PCB
1. Remove 11 screws %and then lift the Cabinet-Rear ^and slide it to rear to remove (see arrow).
2. Remove the Main-PCB &.
1. Remove 5 screws *.
2. Remove the Cabinet-Bottom by pushing the “A” and “B” as shown.
7

6

5

A


B

8


8

8

Figure 3-3
Figure 3-4
3-4 Cabinet-Front and Cabinet-Bottom
Samsung Electronics 3-3
Disassembly and Reassembly

Figure 3-5
3-4 Samsung Electronics
Disassembly and Reassembly
3-5 CD Mecha
13
8
2
765
4
9
31
10
17 16
12
11
20
15
21
14
19
CD SUB PCB
TRAY DISC ASS'Y
TRAY STOPPER
CD MAIN PCB
HOOK
BASE MAIN
18
Refer to the next page
for timming point

Samsung Electronics 3-5
Disassembly and Reassembly
3-5 CD Mecha Continued
3-5-1 Tray Disassembly
3-5-2 Main Disassembly
3-5-3 CD Main PCB Disassembly
*When removing, take extreme care not to damage the hook.
1. Open the Tray Disc Ass’y by turning the Gear-Load %towards “open”, then remove
the Wire-Tray Q.
2. Remove two Tray-Stopper and tray.
1. Remove the Tray-Roulette 3from the Tray-Disc Ass’y 4by releasing the hook.
2. Remove the PCB-Sensor Ass’y 5from the tray by releasing the hook.
3. Remove the Worm-Motor Ass’y ) from the Tray-Disc Ass’y 4.
4. Remove the Cushion-Motor 1from the Tray.
5. Remove the Gear-Roulette 2from the Tray-Disc Ass’y 4by releasing the hook.
1. Remove the Table-Chuck Ass’y 6from the Base-Main by turning it.
2. Push the Slider-Cam !towards right, then lift it up to remove.
3. Remove the Gear-Tray ^from the Base-Main by releasing the fixed hook.
4. Remove the Gear-Converter &from the Base-Main by releasing the fixed hook.
5. Remove the Gear-Cam %from the Base-Main by releasing the fixed hook.
6. Remove the Belt @from the Pulley-Motor Ass’y 7& the Gear-Pulley #.
7. Remove the Gear-Pulley #from the Base-Main by releasing the fixed hook.
8. Remove the Gear-Load $.
9. Remove the Gear-Synchro *.
10. Desolder two soldering points of the CD SUB PCB, then remove it from Base-Main by
releasing the hook.
11. Remove the Pulley-Motor Ass’y 7by releasing the hook.
12. Remove the PCB-SW Ass’y 8by releasing the hook.
1. Remove the Lever-Lifter 9from the Base-Main by releasing two hooks.
2. Remove four Rubber-CD 0from the Lever-Lifter and then remove the Deck-CD “.
3. Remove the Hook.
4. Remove the CD MAIN PCB with the soldering iron.

Figure 3-6
Figure 3-7
3-6 Samsung Electronics
Disassembly and Reassembly
* Reinstall in reverse order.
* Align the Gear-Cam with the Gear-Tray as
shown ing Figure 3-6, then mount the Tray-Disc.
* When assembling the Tray-Disc,take extreme
care not to engage the Gear-Synchro.
Gear-Cam
Gear-Cam
Gear-Cam
Gear-Cam
Timming Point
Gear-Cam
Gear-Synchro
Gear-Disc
Insert

Figure 3-8
Samsung Electronics 3-7
3-6 CD Deck
1. Remove the Shaft !.
2. Lift the P/U @.
Note : Do not to touch the surface of lens.
3. Lift the Center-ring #.
4. Remove the Spring-T/Table $.
5. Remove the Turn-Table (M) %.
6. Remove 2 screws ^and then remove the Spindle-Motor &.
7. Remove the Cover-Gear *by pushing the hook.
8. Remove the Gear (c) (by pushing the hook.
9. Lift the Gear(b) ).
10. Remove the Gear(a) 1.
11. Remove 2 screws 2and the then remove the Feed-Motor 3.
12. Remove the Chassis-Deck (M) 4.
Disassembly and Reassembly
3
4
5
612
21
8
9
10
11
13
14
7

4. Alignment and Adjustments
4-1 Tuner
Samsung Electronics 4-1
FM THD Adjustment
Minimum Distortion (Figure 4-1)
SSG FREQ.
Adjustment
point
(IFT6)
98 MHz
FM DETECTOR COIL
FM Search Level Adjustment
Adjust MSR1 so that “TUNED” of FLT
is lighted (Figure 4-2)
Figure 4-2 FM Auto Search Level Adjustment
Figure 4-1 IF CENTER and THD Adjustment
SSG FREQ.
Adjustment
point
(MSR1)
98 MHz
SEMI-VR(5KB)
FM SSG GND
30 dB
FM SSG
Output
GND
Speaker
Terminal
FM
Antenna
Terminal
Distortion Meter
Input
SET
Input
output
Oscilloscope
75Ω
Dummy
FM IN
FM Antenna
SET
5 KΩ
IFT6
FM T.H.D
MSR1
FM TUNED

4-2 Samsung Electronics
Alignment and Adjustments
4-2 Cassette Deck
4-2-1 To Adjust Tape Speed
1) Measuring tape: i) MTT-111 (or equivalent)
(Tapes recorded with 3kHz)
ii) MTT-5512 (or equivalent)
2) Connect the cassette deck to the frequency counter
as shown in figure 4-3.
1) Before the actual adjustment, clean the replay/recording
head.
2) Measuring tape :
i) MTT-114NA(or equivalent 12.5kHz AZIMUTH control)
ii) MTT-112B(or equivalent : level 200nwb/m)
3) The cassette deck connections are in figure 4-5.
Notes Notes
NOR
SPEED
Control
counter
1
2
Output
(connected
to the frequency
counter)
Turn DSR5 to
left and right 3KHz ±1%
5700 ~ 6300KHZ
Fixed Check
Remark
Standard
To Adjust
Pre-Setup
Item
Step Pre-Setup
Condition
Same as above
1) 1-Deck:MTT-111
2) Press PLAY
SW button
3) 2-Deck:Same
as below
1) 1-Deck:MTT-111
2) 2-Deck:MTT-5512
3) Press Hi Speed
dubbing SW button
HI SPEED
Control
AZIMUTH
1
2
TP3 OUT
(VTVM is
connected to
the scope)
1) Turn the control
knob to as shown
in Figure4-4.
2) Adjust the right
control screw to
playback REV. Mode
Max output
and same phase
(both channels)
After
adjustment
secure it with
REGION
LOCK.
100mV ±0.5dB
L-CH:Turn DSR4L
to the right and
left
R-CH:Fixed
See the
diagram for
adjustment
locations.
Remark
Standard
To Adjust
Pre-Setup
Item
Step Pre-Setup
Condition
Same as
above
After putting MTT-
114NA into Deck 1
1) Press FWD PLAY
button.
2) Press REV PLAY
button.
PLAY MTT-112B
on Deck 1.
PlayBack
out Level
AZIMUTH
1
2
TP3 OUT
(VTVM is
connected to
the scope)
1) Turn the control
knob to as shown
in Figure4-4.
2)Adjust the right
control screw to
playback REV. Mode
Max output
and same phase
(both channels)
After
adjustment
secure it with
REGION
LOCK.
100mV ±0.5dB
L-CH:Turn DSR3L
to the right and
left
R-CH:Fixed
See the
diagram for
adjustment
locations.
Remark
Standard
To Adjust
Pre-Setup
Item
Step Pre-Setup
Condition
Same as
above
After putting MTT-
114NA into Deck 2
1)Press FWD PLAY
button.
2)Press REV PLAY
button.
PLAY MTT-112B
on Deck 2.
Replay
out Level
4-2-2 To Adjust Replay Head
@ Adjust 2-Deck Replay Level
! Adjust 1-Deck Replay Level
TP3
Cassette Deck
output
LINE OUT
Frequency Counter
Figure 4-3
Figure 4-4
Recording /Play head
REVERSE PLAY
AZIMUTH control knob
Figure 4-5
In Out
Cassette Deck Oscilloscope
LINE OUT
TP3
(GND)
VTVM
V H

4-3 CD
Alignment and Adjustments
4-4 Samsung Electronics
4-3-1 To Adjust FOCUS BIAS (STOP mode)
1. Set Volt/Div of the oscilloscope to DC 100mV.
2. Ground the scope input and set the waveform to 0v, DC range.
3. Connect the GND terminal of the oscilloscope to Vref,
and (+) terminal to center of AP1.
4. Set WVR4 to 0mV.
4-3-2 To Adjust Tracking Gain (PLAY mode)
1. Connect the ground terminal of the oscilloscope to Vref and (+) terminal to AP2.
2. Load and play the disc.
3. While the disc is running, adjust the gain with WVR1 as shown below.
4-3-3 To Adjust Focus Gain (PLAY mode)
1. Connect the ground terminal of the oscilloscope to Vref and (+) terminal to AP1.
2. Load and play the disc.
3. While the disc is running adjust the gain with WVR2 as shown in the following figure.
4-3-4 To Adjust E/F Balance (PLAY mode)
1. Set Time/Div of the oscilloscope to 2mS.
2. Set Volt/Div of the oscilloscope to 0.5V.
3. Ground the scope input and set to DC, and then
set the DC range.
4. Connect the ground terminal of the oscilloscope to Vref
and (+)terminal to center to AP2.
5. Load and play the disc.
6. Turn WVR1 counterclockwise to the minimum value.
7. Raise WVR3 and adjust the waveform so that its middle
comes to ground of the oscilloscope, (or until the upper half
of waveform becomes symmetrical to the bottom half,A=B).
8. Adjust WVR1 (arrow) for normal sound.
TP2
TP1
VR
NVR1704 NVR1703 NVR1702 NVR1701
TE CENTER FE CENTER E.F BAL

F.BIAS
0V
Normal Frequency
VOLT/DIV : 0.2V
TIME/DIV : 2mS
VOLT/DIV : 0.2V
TIME/DIV : 2mS VOLT/DIV : 0.2V TIME/DIV : 2mS
Low Frequency High Frequency
A=B
0V 0V 0V
Normal Frequency
VOLT/DIV : 0.1V
TIME/DIV : 2mS
VOLT/DIV : 0.1V
TIME/DIV : 2mS VOLT/DIV : 0.1V TIME/DIV : 2mS
Low Frequency High Frequency
0V
100mV
0V
250mV
0V
100mV

6. Troubleshooting
6-1 Amplifier
6-1-1 Power Malfunction
Front PCB µ-com VDD(5V)
normal? 
UIC1 pins 18,47,90
Replace RIC1
Main PCB RIC1(BA3950) IN: 23V
Input voltage normal?
Yes
Check the Power PCB; 
RD7,8,13(1N5392)

Yes
Front PCB 
Does UX1(12MHz) 
oscillate ?
FRONT PCB PWR-SENS
voltage normal ?
(pin 27 ; 5V)
Check the Main PCB
RD16,RR10,11,12,RC12
RD9
Yes
Front PCB 
When the power is
ON 'H' displays
at pin 5 ?(5V)
Yes
Connect Front PCB and Main PCB.
Check the connector Main PCB.
Wafer MCW2
No

Replace µ-com.
Yes
No
No
No
No
Check the Power PCB : P/T, FUSE
No
Samsung Electronics 6-1

6-1-2 No Output
Yes
AQ103L,R Base B+ ?
Is Mute selected ?
Headphone Jack short ?
Remove it with Remocon.
Replace Headphone jack
soldering condition.
Main PCB AIC101
(STK4121-Option)
pins 9,11,12,14
B+,B- circuits
Check the B+ power 
source part in RD1(PBL403),
RC2,3 and RIC1.
Yes
Confirm for TR short 
replace it.

Check if the output line is
short.
No
No
No
No
Yes
Yes
FIC3(NJU3718) pin 27
Check the "H" ?
No Replace FIC3(NJU3718)

No
6-2 Samsung Electronics
Troubleshooting

6-1-3 Tuner Malfunction(FM/AM)

MZD2 Voltage ok ?
Yes
Check TUNER IC(LA1836)
pin 10 ; 8.6V
pin 14 ; 7.2V
AM ; 0V ?
Yes
LC72131
CONTROL ok?
Yes
FM VT 
LC72131 pin 20
1.7V 7.5V ?

Yes
AM VT
LC72131 pin 20 Check the LC72131
CONTROL ok?
Yes
Yes
Check MIC2
pin 20 ?
LPF(MLPF 1L/1R)
output ok? Check TDA7318 function ok? Check FEP interior
pattern, and any line
disconnections.
No
Yes
Check for µ-com IC
Replace LC72131
No

MZD1 (5.6V) Voltage ok?
MIC2 (LC72131) FM/AM BAND
Switching ok?
No
No
No
No
No
No
No
0.9V 7V?
Check MZD2(8.2V),MR29
No

1) Power section
defective?
2)LC72131 Oscillator
(HX1:7.2MHz)ok?
3)System line ok?
Samsung Electronics 6-3
Troubleshooting

6-1-4 VFD Malfunction
Yes
Connector inserted
correctly?
No
Yes
Check voltage : AC 4.8V 
at FRONT-PCB FLT?
No Check Main-PCB Front PCB
connection and the voltage of
CCW1, pins 1,2(AC4.8V)
Yes
Check voltage at UIC1 
pin 48(-33V)
No Check the voltage of RZD1(-33V)
Reinsert the connector.



Replace UIC1


6-4 Samsung Electronics
Troubleshooting